To have names of months in English and not in current langage version of R
> Sys.setlocale(category = "LC_TIME", locale="en_GB.UTF-8") [1] "en_GB.UTF-8" > x <- seq(from=as.Date("2000-04-01"), length.out=100, by=1) > y <- rnorm(length(x), 5,2) > plot(x, y) > Sys.setlocale(category = "LC_TIME", locale="") [1] "fr_FR.UTF-8"